power steering seems to be very very stiff

what was the steering like before you changed belts? you mite have to change out the steering pump, i had the same issue with my dodge, mostly cuz i was doin donuts at high spped, high rpms and low steering fluid, but changed my pump and solved the problem, hope it helps

I have had numerous fords that had power steering ailments, once i packed a steering stabilizer full of mud on a very muddy road, didnt have trouble until the mud dried up in it and i had real stiff steering, so make sure thats not messed up. Nobody ever changes the fluid in them, i have a old 75 F150 and have been thru several steering sectors, I now pull the return line off and drain it out now and then, put the wheels in the air and roll the steering back and forth, i have seen chunks come out, and put fresh stuff in. and work the steering back and forth without the motor running to prime it up. they last a lot longer. Also make sure the pump turns freely without the belt on. good luck